1 definition
by
Bofo

This has also been spoken as the "guy nod" due to the fact that only guys seem to be the ones that do this, and at ages from middle school on up.

Nod of acknowledgement can be seen when walking through the halls of a school, I guy sees a girl that he knows, and gives her the guy nod to acknowledge the fact that he sees her, but not to draw too much attention to either himself or the situation that's occuring